Helmet

ABSTRACT

A helmet that ventilates a user&#39;s head more efficiently. The relative movement of the helmet to air in the environment creates an airflow that enters intake openings designed to allow increased amounts of airflow into the helmet. The intake openings are positioned on an inclined plane near a user&#39;s forehead such that the intake openings extend upwardly and outwardly away from a user&#39;s eyes, thereby reducing the impact of a larger intake opening on the user&#39;s field of vision. Inside the intake openings, air is collected in a plenum and then guided into air channels leading into the head cavity. The air channels direct the airflow throughout the head cavity allowing the fresh air from the environment to exchange heat and perspiration from a user&#39;s head and are designed to inhibit obstruction of the air channels by the liner. Air channels also direct airflow to an exhaust such that the airflow can remove heat and perspiration from the helmet cavity and the helmet surface adjacent the exhaust is contoured to facilitate removal of air from the helmet. The liner is designed for easier installation and replacement.

RELATED APPLICATIONS

The present application claims priority to U.S. Provisional Patent Application Ser. No. 60/558241, filed Mar. 31, 2004.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to head protection for operators or riders of motorized vehicles.

2. Description of the Related Art

Use of head protection is often recommended and sometimes required by law while operating motorized vehicles, such as when riding a motorcycle. Helmets are available in a variety of styles but the principle design consideration for all helmets is protection from serious head injuries during accidents.

Generally, motorcycle helmets that comply with the safety standards include a thin, hard outer shell and an impact-absorbing, thicker inner shell made of a rigid foam, such as Expanded Polystyrene (“EPS”). While some prior art motorcycle helmets meet the safety standards and provide protection against head injuries, prior art motorcycle helmets are uncomfortable for a number of reasons. For many years, motorcycle riders have complained about the heat retention properties of today's helmets. Especially for riders in warm climates, motorcycle helmets become very uncomfortable as they trap heat around a person's head. The problem of heat retention in helmets is amplified for off-road motorcycle riders, who often enjoy riding in desert settings, by the vigorous, athletic exertions involved in the sport. Not only does the heat retention in today's helmets causes excessive perspiration from the heads of riders, it can lead to heat exhaustion, limiting the length of time a rider can enjoy off-road riding.

Some helmets on the market today have tried to address these problems with ventilation holes formed through the outer shell and EPS layer for the apparent purpose of allowing air into the head cavity. These holes are often ineffective because they simply do not allow enough air into the head cavity to provide significant cooling to the user.

Some helmets on the market today offer helmets with air intake scoops at the top of the helmet's eye opening. The scoops are intended catch air and direct it into the head cavity. Unfortunately, these air scopes typically have very small openings, often about ⅛ inch or ¼ inch, and therefore catch very little air and are similarly less effective in flowing cooling air into the head cavity.

Further, today's helmets have limited air flow within the helmet itself. In particular, helmets on the market today have small channels that are easily occluded by the liner. Moreover, the channels are often formed in such a manner that continuous air flow through the channels is disrupted. As such, these helmets have less effective channeling systems such that any air that does enter the head cavity simply cannot create the airflow needed to adequately cool a user's head.

Furthermore, today's helmets are not very effective in removing heated air and perspiration from the head cavity. Most helmets on the market today have small exhaust openings that are not particularly effective in permitting the air from the inside of the helmet to be removed.

Additional problems with today's helmets relate to the helmet liners included in helmets as a soft cushion between a user's head and the helmet's impact absorbing layer. The liners in today's helmets are often pressed against the impact absorbing layer by a user's head such that the liner impedes, or sometimes even blocks, airflow in the head cavity. This problem is amplified when the liner becomes saturated with sweat as a wet liner will adhere to the impact absorbing layer and allow even less air through an air channel than a dry liner. Further, a sweat saturated liner is uncomfortable against a riders head.

While liners are typically removable and replaceable, poor design of today's liners makes removal and replacement inconvenient. Helmet liners on the market today include a series of ears with holes in the middle designed to mate with clips within helmet's shell. The clips on today's helmets are hidden within plastic molding around the helmet's eye opening and have a small circular protrusion that a user must mate with the hole in the liner's ear. Because the clips are hidden within the molding, the user must probe the ears under the molding and blindly match the hole to the protrusion. This design makes replacing a helmet liner a time consuming and bothersome chore.

In sum, today's helmets are not very effective in addressing the problem of heat retention associated with helmets. The problem of heat retention in helmets often leads riders to loosen the fit of their helmets or even remove their helmets while riding, thereby defeating the safety function. Considering the shortcomings in prior art helmets, there exists a need for a helmet that is better at capturing air from the environment and introducing it into the interior of the helmet. Further, there is a need for a helmet that allows better airflow through the head cavity, and exhausts heated air and perspiration to the environment more efficiently. Moreover, there exists a need for a helmet with a liner that is less likely to obstruct airflow within the head cavity and that can be replaced quickly and easily.

SUMMARY OF THE INVENTION

The aforementioned needs are satisfied by the helmet of the present invention which in one aspect comprises a helmet having an inner and an outer surface that is sized so as to encompass the head of the operator. The outer protective shell defines an eye opening that is positioned proximate the operator's eyes when the operator is wearing the helmet. The outer protective shell also defines at least one exhaust opening located adjacent the back of the head of the operator when the operator is wearing the helmet.

In this aspect, the helmet further comprises an inner protective layer that is positioned inward of the outer protective shell so as to substantially cover the inner surface of the outer protective shell. The inner protective layer includes a plurality of air channels extending from the at least one intake positioned adjacent the opening in the eye opening to the exhaust openings. In this aspect, the at least one input is formed in the inner protective layer such that the plane of the intake opening has a component that is perpendicular to the direction of travel of the operator such that the air is injected into the plurality of channels as a result of the operator traveling in the direction of travel.

Since the at least one opening is formed in the eye opening, the opening can be quite large and capable of gathering a substantial amount of air. Moreover, since the at least one opening has a component that is perpendicular to the direction of travel, air can be injected into the channels at a relatively high rate of speed thereby improving air flow through the helmet.

In another aspect of the invention, an intake plenum is formed on the intake surface of the helmet. The intake plenum in one embodiment is comprised of a plurality of openings formed along the eye opening so as to be able to gather air for subsequent delivery into the channels. The use of such an intake plenum results in better air flow through the helmet.

In another aspect of the invention, the helmet further comprises a liner that is interposed between the inner protective layer and the operator's head. The liner is preferably inhibited from being pushed into the channels at a position proximate the user's forehead when the user is wearing the helmet so as to allow for better air flow through the channels. Moreover, the liner is attached, in one aspect, to the helmet via attachment tabs that are sized so as to be positioned within mating openings. The attachment tabs include a surface that is perpendicular to the plane of the attachment tab that mates with a mating surface in the helmet. Hence, the liner can be positioned within the helmet and secured therein more easily as a result of the tabs being mated with the openings.

In yet another aspect of the invention, the outer shell of the helmet defines a first air flow surface and a second air flow surface wherein the air flows over the second surface at a slower rate than the first surface. The exhaust openings are, in this aspect, preferably positioned on the second surface immediately adjacent the interface with the first surface such that a relative vacuum is formed adjacent the exhaust openings to thereby facilitate removal of the air. In this aspect, air flow through the helmet is enhanced as a result of the relative vacuum.

Hence, from the foregoing, the design of the helmet in each of these aspects is adapted to facilitate air flow through the helmet. As such, the user is provided with greater cooling than with prior art helmets. These and other objects and advantages will become more apparent from the following description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. A part that appears in more than one drawing is in many instances identified by the same reference numeral throughout the drawings to facilitate cross-reference among the various views represented. In some of the Figures, for improved clarity of presentation, not all of the parts that appear in the figure are identified by their respective numerals.

FIG. 1 is an exploded perspective view of one embodiment of the helmet.

FIG. 2 is a front view of one embodiment of the helmet of FIG. 1.

FIG. 3 is a cross section of one embodiment of the helmet of FIG. 1.

FIG. 4 is front view of the inner protective layer and intake cover of one embodiment of the helmet of FIG. 1.

FIG. 5A is a cross section view of one embodiment of the helmet of FIG. 1 showing the liner attachment mechanism.

FIG. 5B is a bottom view of the liner attachment assembly of FIG. 5A.

FIG. 6 is a side view of one embodiment of the helmet of FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS

Reference will now be made to the drawings wherein like numerals refer to like parts throughout. FIG. 1 illustrates an exploded view of the disclosed helmet 100 according to one embodiment. FIG. 1 illustrates an outer protective shell 102 and an inner protective layer 104 which combine to form a head cavity 106. The outer shell 102 includes an eye opening 110, through which a user can see while wearing the helmet, an eye opening perimeter 112, and at least one exhaust opening 114, not shown in FIG. 1. The outer shell may also include a forehead member 116 located at or near the eye opening perimeter 112.

As illustrated in FIG. 1, the outer shell 102 includes a skull protection section 117 and a chin protector 119 with the eye opening 106 interposed therebetween. The chin protector 119 is integrally attached to the skull protection section 117 and extends outward therefrom in a known manner and is positioned so as to provide protection to the lower face of the user when the user is wearing the helmet 100. The chin protector 119 substantially covers an operator's jaw when the helmet 100 is worn. The chin protector 119 and skull protection section 117 communicate with the eye opening perimeter 112 to define the eye opening 110.

When the helmet is worn by an operator, the eye opening perimeter 112 and skull protection section 117 generally meet at a location near the operator's forehead, slightly above the operator's eyes. The eye opening perimeter 112 and chin protector 119 generally meet at a location slightly below the operator's nose. In this orientation, the eye opening 110 is approximately the same shape as typical eye goggles worn by many operators of motorized vehicles, such that typical goggles substantially cover the exposed portion of an operator's face, with the exception of the nose, and generally substantially occupy the eye opening. In this arrangement, intake openings 120 generally spaced along an eye opening surface 131 of an inner protective layer 104 adjacent the forehead member 116 are generally above a user's goggles and not obstructed by a user's goggles. As will be discussed below, this arrangement can help direct airflow to the intake openings 120.

The skull protection section 117 is integrally formed of a rigid material such as plastic, fiberglass, carbon fiber, and/or Kevlar and is sized so as to cover substantially the skull of the user. As will be described in greater detail hereinbelow, the skull protection section 117 defines an upper air flow surface 121 and a lower air flow surface 123 with an interface comprising a raised ridge 125. The air flow surfaces 121 and 123 along with the interface 125 assist in removing air from the interior of the helmet 100 in the manner that will be described in greater detail hereinbelow.

The inner protective layer 104 shown in FIG. 1 fits within the outer shell 102 and is permanently attached therein. A first surface 105 of the inner protective layer 104 substantially covers an inner surface 122 of the skull protection section 117 of the outer shell 102. In this arrangement, the inner protective layer 104 is positioned between the outer shell 102 and an operator's skull when the helmet 100 is worn. The inner protective layer 104 is preferably constructed of an impact absorbing material such as molded expended polystyrene (“EPS”). As is also illustrated in FIG. 1, the inner protective layer also defines a eye opening surface 131 that is positioned immediately adjacent the eye opening 110. As will be discussed in greater detail below, the eye opening surface 131 is preferably angled and has plenums formed therein so as to facilitate air flow through the helmet 100.

Air channels 124 are formed on a second surface 107 of the inner protective layer 104. At least one of the air channels 124 extends along the curved second surface 107 from a location at or near the forehead member 116, e.g., initiating at the eye opening surface 131 to a location preferably near the rear of an operator's skull. A plurality of air channels 124 can be included with more than one extending from the forehead member 116. One or more optional plenum 134, formed on the eye opening surface 131 of the inner protective layer 104, are also shown in FIG. 1. The air channels 124 and plenum 134 will be described in greater detail below.

FIG. 1 also shows a liner member 126. The liner member 126 can be any shape, but the preferred liner member 126 is generally thin with a rectangular shape, such as that shown in FIG. 1. The liner member 126 is preferably permanently attached to the second surface 107 of the inner protective layer 104 and generally follows the curved shape of the second surface 107, spanning over one or more air channels 124. Placement of the liner member 126 on the second surface 107 can vary, but the typical location of attachment is at or near the forehead member 116 with a lateral orientation, substantially parallel to an operator's forehead. More than one liner member could be utilized at different locations on the second surface 107. The liner member 126 can be made from a variety of suitable materials such as plastic or other somewhat rigid, preferably waterproof, materials. The liner member 126 serves a number of functions described in greater detail hereinbelow.

FIG. 1 also depicts a liner 132. The liner 132 is generally shaped to substantially cover the second surface 107 of the inner protective layer 104. The liner 132 is preferably air permeable and typically constructed of material and/or foam or padding. The liner 132 is positioned between the relatively hard inner protective layer 104 and an operator's head to provide cushioning. The liner 132 is removably attached to the helmet 100 with attachment mechanisms such as snaps, buttons, or other known mechanical attachment devices generally positioned near the forehead member 116 and near the rear of an operator's head. The liner 132 shown in FIG. 1 also includes a liner connector 147. The liner connector 147 includes a liner rim 148 that traces along a forehead section 133 of the liner 132 and at least one liner tab 149 extending from the liner connector 174. The liner rim 148 is curved with roughly the same curvature as the eye opening perimeter 112. FIG. 1 shows a series of liner tabs 149 spaced generally symmetrically along the liner rim 148. The liner connector 147 is part of a novel retention mechanism 144, which will be described in detail below.

FIG. 1 also shows an intake covering 130. The intake covering 130 generally covers the eye opening surface 131 and is positioned adjacent to the eye opening 110 and eye opening perimeter 112. As depicted in FIG. 1, the air intake covering 130 is preferably a thin plastic piece with a crescent shape, with a curvature generally the same as the eye opening perimeter 112. The intake covering 130 includes at least one air intake opening 120. The intake covering 130 shown in FIG. 1 includes screen members 133 that span across a series of intake openings 120 to filter out dirt and debris. In some preferred embodiments, the intake covering 130 curves following the eye opening perimeter 112 and is approximately ¾ inch by 8 inches. The intake cover 130 shown in FIG. 1 also includes a liner attachment 145 described in greater detail herein below in reference to FIG. 5A and FIG. 5B. The liner attachment receiver 145 includes liner attachment retainers 150, a receiver rim 151, and receiver openings 146 (not shown) which are also part of the retention mechanism 144 described below. The receiver rim 151 has generally the same shape and dimensions as the liner rim 148 such that the receiver rim 151 and the liner rim 148 mate when the liner 132 is attached to the helmet 100. Further, the receiver openings 146 are spaced along the attachment receiver 145 at locations corresponding to the liner tabs 149.

FIG. 2 shows a front view of the helmet 100. As can be appreciated from FIG. 2, the eye opening surface 131 is angled such that the air intake openings 120 communicate with air in the environment near the eye opening 110. The eye opening surface 131 of the inner layer 104 is preferably angled such that the surface 131 has a component that is normal to the direction of travel. When a user operates a motorized vehicle while looking in the direction of travel, movement of the helmet 100 relative to the environment creates a flow of air in the direction opposite the direction of travel. Intake openings 120 oriented normal or oblique to the airflow therefore capture airflow. Generally, larger and increased numbers of intake openings 120 can catch larger amounts of airflow. In embodiments in which the forehead member 116 curves around the operator's forehead, intake openings 120 can be spaced along the eye opening surface 131. The embodiment depicted in FIG. 2 shows five intake openings 120 spaced along the eye opening surface 131 and the intake opening cover 130 with screen members 133 spanning over each one.

FIG. 2 also shows optional intake openings 120 located in the skull protection portion 117 of the outer shell 102 and in the chin protector 119. FIG. 2 also shows exhaust openings 114 which communicate with the environment near lower airflow surface 123, not shown in FIG. 2, and with air within the head cavity 106. Further details of the exhaust openings will be provided below.

Considering the front view shown in FIG. 2, airflow created from a forward movement of the helmet would be generally normal to the page. As can be appreciated from FIG. 2, airflow near the eye opening 110 contacts the helmet 100 and a user's face or eye goggles (not shown) and to at least some extent is rebounded upwards towards the openings 120. FIG. 3 illustrates this air flow pattern in greater detail. As illustrated, a portion of the air 211 flows directly into the openings 120. Similarly, the angled surface 131 is positioned immediately proximate the goggles 212 of the user such that a portion of the air 214 hitting the goggles 212 is rebounded into the openings 120. In this sort of arrangement, the amount of airflow captured by the intake openings 120 can be significant. The embodiment shown in FIG. 2 includes five air intake openings 120 in the forehead member 116 with a total surface area of approximately 3 square inches.

FIG. 3 also shows the forehead member 116 and intake opening 124 on a plane oriented at an angle Θ from horizontal. By orienting the eye opening surface 131 on an upwardly angled plane above a rider's forehead, the surface area of the intake opening 120 can be increased with little or no decrease in the user's field of vision. In this arrangement, the effective size of the intake opening 120 can be increased by increasing the width of the surface 131 and, thus, the openings 120 upwardly and outwardly relative to a user's face and eyes. In one particular implementation, the surface 131 is angled at an angle Θ within the range of 35 degrees to 45 degrees from horizontal when the helmet 100 is sitting on the flat surface in the manner shown in FIG. 3, and in a more specific implementation is angled at about 40 degrees from horizontal when the helmet 100 is sitting on a flat surface. In one implementation, the width of the surface 131 is in the range of ¾ inch to 1 inch and is more specifically ⅞ inch.

FIG. 3 also shows the plenums 134 formed in the surface with a width B and depth C. The plenum 134 is generally a cavity formed in the surface 131 of the inner protective layer 104 that collects air entering the air intake openings 124. In this arrangement, the plenum 134 is curved, generally following the forehead member 116 or eye opening perimeter 112. The width and depth of the plenums 134 can vary, with greater values for these dimensions allowing the plenum 134 to hold more air, in general. In preferred embodiments, plenum width is greater than or equal to air intake opening width 120, and the intake opening 120 is generally aligned with the plenum 134 such that air can flow through the intake opening 120 into the plenum 134. In some preferred embodiments, the total volume of the plenum 134 is approximately 40 cubic centimeters.

The plenum 134 of some preferred embodiments also includes a transition corner 136 that is optionally rounded, creating a relatively smooth corner between the plenums 134 and the air channels 124. This rounded transition 136 provides a less abrupt change to the direction of the airflow as it moves from the plenum 134 to the air channels 124. In embodiments that do not include a plenum 134, the rounded transition 136 may be positioned on the air channels 124 between the intake opening 120 and the air channels 124.

FIG. 3 also shows the liner member 126 positioned against the inner protective layer 104. The liner member 126 is secured to the inner protective layer 104 and extends across the air channels 124 to generally enclose the portion of the air channel 124 proximate the plenums 134. The liner member 126 is preferably secured to the inner layer 104 at a position such that it is interposed between the user's forehead and the inner layer 104. Generally, the user's forehead is positioned flush against the inner layer when the user is wearing the helmet and the liner member 126 provides a rigid barrier that inhibits the user's forehead from pushing the liner 132 into the channels 124. Glue or other connectors, such as rivets, can be used to attach the liner member 126 to the inner protective layer 104. In one implementation, the width of the liner member 126 is approximately 1¼ inches, but it will be appreciated that this width can vary depending on the helmet configuration. The liner member 126 may optionally include ventilation openings 142 that allow some airflow through the liner member 126. Also, the liner member 126 could be attached to the liner 132 as an alternative to, or in addition to, attachment to the inner protective layer 104.

In the arrangement shown in FIG. 3, enclosing the air channel 124 at the location where the plenum 134 and air channels 124 has additional advantages. At this location, the airflow passes from the plenum 134 into the air channels 124, changing direction as the airflow passes around a transition corner 136. In this arrangement, the liner member 126 aids in this transition by reducing the tendency for the air to continue to flow along the plane of surface 131 and/or disperse. In other words, by covering the beginnings of air channels 124, the liner member 126 compliments the air channels 124 in restricting the directions in which the air can pass, thereby directing air into and through the air channels 124.

Directing the airflow in the air channels is similarly assisted by side walls 140 in the air channels 124, shown in FIG. 3. The side walls 140 restrict airflow in lateral directions and thus facilitate air flowing in the direction toward the back of a user's head. By flowing the air through the channels 124 of the helmet 100 at a high rate of speed, e.g., the speed of travel of the motorcycle, a substantial amount of convection cooling can occur within the helmet. Some embodiments include channels 124 having side walls 140 with increased heights near the air intake opening 120 or plenum 134, creating a relatively deep portion of the air channel 124. Testing has shown that side walls 140 with heights of approximately ¼ inch and widths of approximately ⅝ inch are effective in facilitating air flow through the channels 124. These arrangements generally form channels 124 with three-sided, rectangular cross sections or a semi-circular cross section. Typically, the side walls 140 taper from the transition 136 towards the crown of the helmet.

Referring now to FIG. 4, in one implementation, the helmet includes five air channels 124 spaced along the plenum 134 so as to be distributed over the surface 107 of the inner layer 104. In some embodiments, these channels 124 are spaced approximately ¾ inch apart. As is illustrated in FIG. 4, the plenums 134 in this embodiment comprise left and right plenums 134 a, 134 c and a center plenum 134 b. The left and right plenums 134 a, 134 c provide air to two of the channels 124 that extend along the side of the user's head and the center plenum 134 b provides air to a channel 127 that extends along the top of the user's head.

Referring again to FIG. 3, the thickness of the inner protective layer 104 can vary at different locations within the helmet 100, but generally a minimum thickness is needed for safety considerations. As such, an increased thickness may be necessary to compensate for the channeling 124. In one implementation, the minimum thickness is approximately 1 3/10 inches to 1½ inches.

As shown in FIG. 3, at least one exhaust opening 114 is formed in the inner layer 104 and the outer shell 102. The exhaust openings 114 are located in the skull protection portion 117 of the outer shell 102. Typically, the exhaust openings 114 communicate with at least one air channel 124 and the environment. Exhaust channels 125 extend through the inner protective layer 104 from some location in the head cavity 106 or air channel 124 to an exhaust opening 114. The exhaust channels 125 typically have a circular cross-section and may be drilled or molded into the helmet 100. Any cross-sectional shape would suffice. An exhaust plenum 118 is optionally located between the exhaust opening 114 and the exhaust channel 125. Further, FIG. 3 shows air channels 124 situated near the neck opening 108 of the helmet such that neck exhaust openings 129 communicate with air channels 124 and the environment allowing air to flow from the air channels and/or head cavity 106 to the environment.

The airflow within the helmet 100 will now be described in reference to FIGS. 3 and 4. The plenum 134 allows an increased amount of air from the environment to enter the intake openings 120. The difference in size of the plenum 134 and air channels 124 can in turn enhance the airflow into the air channels 124 by producing a venturi effect. As air flows through the relatively large plenum into the relatively narrow air channels, the flow rate increases into the more narrow air channels 124. The air channels 124 generally channel air through the head cavity in a distributed fashion, preferably with at least one of the air channels 124 extending to locations behind an operator's head.

As the airflow continues through the air channels 124 toward the exhaust openings 114, the fresh air combines with perspiration and air warmed by an operator's head within the head cavity. In embodiments in which the side walls 140 taper, the tapering allows some lateral movement of airflow and further facilitates the interchange of air from the environment with heated air and perspiration. This interchange of air increases the comfort of a user by removing perspiration and heat from a user's head. Similarly, airflow through the channels 124 may also serve to remove perspiration and heat from the liner 132, providing further comfort to users. The exhaust openings 114 located behind a user's head assist in removing the heated air and perspiration. The exhaust function will be discussed in more detail below.

FIGS. 5A and 5B illustrate a retention mechanism 144 that holds the liner 132 in contact with the intake covering 130. Specifically, the retention mechanism 144 comprises a receiver structure 145 formed on the intake covering 130 and a liner attachment member 148 attached to the liner. The receiver structure has three walls 149, 150, 153 positioned orthogonal to each other so as to define a recess 152 with a generally U-shaped cross section. A tab 151 is positioned at the end of the wall 150 which aids in retaining the liner attachment member 148 in contact with the intake covering 130 in the manner that will be described herein below. The wall 153 defines an opening 146 that is adapted to receive the liner attachment member 148.

The liner attachment member 148 includes a main section 157 that has a cross-section which matches the cross section of the U-shaped recess 152. At one end of the main section 157, a flanged protrusion 154 is attached. The flanged protrusion 154 preferably has a cross sectional area that is greater than the opening 146 but is formed of a deformable material such as plastic.

In operation, the flanged protrusion is positioned adjacent the opening 146 in the recess 152 and the flanged protrusion is forced through the opening thereby elastically deforming the flanged protrusion 157. The rear surface 156 of the main section 157 of the liner attachment member 148 is urged passed the tab 151, which is preferably made of an elastically deformable material e.g., plastic, such that the main body 157 is flushly positioned within the recess 152 when the flanged protrusion 154 is inserted through the opening 146.

Hence, both the engagement between the flanged protrusion 154 and the inner surface of the wall 153 and the tab 151 securely retain interconnection between the liner 126 and the intake covering 130. However, the use of deformable elastic material allows disengagement between the liner member 148 and the receiver structure 145 by pulling with sufficient force to deform the flange protrusion 154 sufficiently to extract it out of the opening 146 and also with sufficient force to simultaneously deform the tab 151 to remove the main body 157 from the recess 152.

As is illustrated in FIG. 5B, the receiver structure 145 and the liner attachment member 148 extend in a direction parallel to the perimeter of the eye opening 110. Moreover, in this embodiment, the flange protrusion member 154 and the tab 151 inhibit movement in a direction that is generally perpendicular to the direction of the perimeter. Advantageously, the opening 146 and, in this embodiment, the recess 152 are sized so as to correspond to the size of the tab 148. Hence, the user can more easily position the tab 148 within the appropriate recess 152 as the mating structures are preferably similar sizes. As is illustrated in FIG. 5B, in this implementation there are three tabs 148 a-148 c and three similarly sized openings 145 a-145 c spaced about the upper perimeter of the eye opening 110 to thereby retain the liner 126 in the interior surface of the helmet 100.

FIG. 6 shows the upper airflow surface 121 and the lower airflow surface 123 located on the skull protection section 117 of the outer shell 102. The raised ridge 125 generally defines the interface of the upper and lower air flow surfaces 121 and 123. Exhaust openings 114 are located on the lower airflow surface, preferably immediately adjacent the raised ridge 125.

Movement of the helmet during operation of a motorized vehicle also creates airflow against and around the outer shell 102. The upper airflow surface 121 will experience airflow at a first flow rate X and the lower airflow surface 123 will experience airflow at a second flow rate Y. Generally, the first flow rate X will be greater than the second flow rate Y. The difference between the second flow rate Y and the first flow rate X creates an area 171 of decreased pressure near the interface 125 of the airflow surfaces 121 and 123. In one aspect of the invention, exhaust openings 114 are positioned at or near the interface 125 such that the exhaust openings 114 experience a vacuum from the area of decreased pressure 171. In this arrangement, air is drawn from within the exhaust plenum 118 (FIG. 3) and/or exhaust channels 125, through the exhaust opening 114. This suction of air compliments the airflow within the head cavity 106 to exhaust heat and perspiration. In other words, airflow within the head cavity 106 generally continues toward and through the exhaust openings 114, and, at the same time, the pressure differential near the exhaust openings 114 pulls air through the exhaust openings 114. By exhausting air from the head cavity 106, heat and moisture are effectively removed. This function can be achieved with a number of designs and arrangements of ridges and exhaust openings.

Hence, from the foregoing, it will be appreciated that the helmet is better adept at circulating air through the interior to cool the user when riding. The openings to allow the air in are larger due at least in part to their placement on the exposed angled edge of the inner protective layer at the eye opening. Moreover, the use of plenums greatly facilitates gathering of air to increase airflow through the channels and this air flow is less likely to be impeded by the liner as the channels are better protected. The air is more easily removed due to the configuration of the outer shell of the helmet and the placement of the exhaust opening.

Advantageously, the liner is also easier to remove for cleaning and replacement purposes. Thus, the illustrated embodiment of the helmet represents an improvement over helmets of the prior art in a number of different manners.

Although the preferred embodiments of the present invention have shown, described and pointed out the fundamental novel features of the invention as applied to those embodiments, it will be understood that various omissions, substitutions and changes in the form of the detail of the device illustrated may be made by those skilled in the art without departing from the spirit or scope of the present invention. Consequently, the scope of the invention should not be limited to the foregoing description but should be defined by the appended claims. 

1. A safety helmet for operators of motorized vehicles, the helmet comprising: an outer protective shell having an inner and an outer surface that is sized so as to encompass the head of the operator wherein the outer protective shell defines a eye opening that is positioned proximate the operator's eyes when the operator is wearing the helmet and wherein the outer protective shell defines at least one exhaust opening located adjacent the back of the head of the operator when the operator is wearing the helmet; an inner protective layer positioned inward of the outer protective shell so as to substantially cover the inner surface of the outer protective shell wherein the inner protective layer includes a plurality of air channels extending from at least one intake positioned adjacent the opening in the eye opening to the exhaust openings wherein the at least one intake is formed in the inner protective layer such that the plane of the intake opening has a component that is perpendicular to the direction of travel of the operator such that air is injected into the plurality of channels as a result of the operator travelling in the direction of travel.
 2. The helmet of claim 1, further comprising a liner that is attached to the inner protective layer.
 3. The helmet of claim 2, wherein the air channels are formed in an inner surface of the inner protective layer such that the liner is positioned proximate to the liner so that air travelling through the air channels cool the liner.
 4. The helmet of claim 3, further comprising at least one channel members extending across the plurality of channels at a location adjacent the forehead of the operator such that the at least one channel member inhibits the liner from entering the channel at a location adjacent the forehead of the operator to thereby occlude air flow.
 5. The helmet of claim 1, wherein the inner protective layer and the outer shell define at the eye opening an intake surface which is in fluid communication with the plurality of air channels.
 6. The helmet of claim 5, wherein the intake surface extends across substantially the entire width of the eye opening.
 7. The helmet of claim 5, wherein a portion of the inner protective layer adjacent the intake surface is removed so as to define an intake plenum wherein air can be accumulated prior to travelling through the plurality of air channels.
 8. The helmet of claim 7, wherein five air channels are spaces approximately ¾ inch apart
 9. The helmet of claim 1, wherein the outer shell defines a first air flow surface wherein air flows over the first air flow surface at a first rate and a second air flow surface wherein air flows over the second air flow surface at a second rate less than the first rate and wherein the exhaust openings are positioned on the second air flow surface immediately adjacent the interface with the first air flow surface such that a relative vacuum is formed immediately adjacent the exhaust openings in the outer shell to thereby facilitate removal of air from the plurality of air channels.
 10. A safety helmet for operators of motorized vehicles, the helmet comprising: an outer protective shell having an inner and an outer surface that is sized so as to encompass the head of the operator wherein the outer protective shell defines an eye opening that is positioned proximate the operator's eyes when the operator is wearing the helmet and wherein the outer protective shell defines at least one exhaust opening located adjacent the back of the head of the operator when the operator is wearing the helmet; an inner protective layer positioned inward of the outer protective shell so as to substantially cover the inner surface of the outer protective shell wherein the inner protective layer includes a plurality of air channels formed in an inner surface of the inner protective layer with at least one of the channels extending from at least one intake opening to the at least one exhaust opening; a liner positioned between the inner protective layer and an operator's head when wearing the helmet and a channel member positioned between the liner and the channels to inhibit the liner from entering the channels to inhibit air flow.
 11. The helmet of claim 10, wherein the at least one intake opening is formed in the inner protective layer and positioned adjacent to the eye opening, having an intake plane forming a generally upward angle with respect to the direction of travel of the operator such that air enters the intake as a result of the operator moving in the direction of travel.
 12. The helmet of claim 10, further comprising at least one plenum positioned between the at least one intake and the at least one air channel such that air passing through the intake can accumulate in the plenum.
 13. The helmet of claim 10, wherein the outer shell defines a first air flow surface wherein air flows over the first air flow surface at a first rate and a second air flow surface wherein air flows over the second air flow surface at a second rate less than the first rate and wherein the exhaust openings are positioned on the second air flow surface immediately adjacent an interface between the first air flow surface and the second air flow surface such that a relative vacuum is formed immediately adjacent the exhaust openings in the outer shell to thereby facilitate removal of air from the plurality of air channels.
 14. The helmet of claim 13, wherein the first airflow surface includes a raised portion positioned at the interface of the first airflow surface and the second airflow surface designed to exaggerate the difference between the first airflow rate and the second airflow rate.
 15. The helmet of claim 10, further comprising a detachable retention mechanism for securing the liner in the interior of the helmet, the detachable retention mechanism comprising: at least one opening extending in a direction that is generally parallel to a perimeter of the eye opening wherein the at least one opening defines a recess with at least one blocking surface that is generally normal to a plane of the at least one opening; at least one tab having a main body and an engagement surface extending therefrom, wherein the main body is sized so as to be positioned in the recess defined by the opening such that the engagement surface of the tab engages with the blocking surface of the at least one opening so as to inhibit removal of the tab from the opening to maintain the liner in an engaged position with the helmet wherein the tab is deformable such that the tab can be deformed so as to disengage the engagement surface from the blocking surface to permit the tab to be removed from the opening to facilitate removing the liner from the helmet.
 16. A safety helmet for operators of motorized vehicles, the helmet comprising: an outer protective shell having an inner and an outer surface that is sized so as to encompass the head of the operator wherein the outer protective shell defines a eye opening that is positioned proximate the operator's eyes when the operator is wearing the helmet and wherein the outer protective shell defines at least one exhaust opening located adjacent the back of the head of the operator when the operator is wearing the helmet; an inner protective layer positioned inward of the outer protective shell so as to substantially cover the inner surface of the outer protective shell wherein the inner protective layer includes a plurality of air channels extending from at least one intake positioned adjacent the opening in the eye opening to the exhaust openings, and wherein the outer shell defines a first air flow surface wherein air flows over the first air flow surface at a first rate and a second air flow surface wherein air flows over the second air flow surface at a second rate less than the first rate and wherein the exhaust openings are positioned on the second air flow surface immediately adjacent the interface with the first air flow surface such that a relative vacuum is formed immediately adjacent the exhaust openings in the outer shell to thereby facilitate removal of air from the plurality of air channels.
 17. The helmet of claim 16, wherein the outer shell includes a generally lateral protrusion in a rear portion of the outer surface of the outer shell positioned between the first airflow surface and the second airflow designed to exaggerate the difference between the first rate and the second rate.
 18. A safety helmet for operators of motorized vehicles, the helmet comprising: an outer protective shell having an inner and an outer surface that is sized so as to encompass the head of the operator wherein the outer protective shell defines a eye opening that is positioned proximate the operator's eyes when the operator is wearing the helmet and wherein the outer protective shell defines at least one exhaust opening located adjacent the back of the head of the operator when the operator is wearing the helmet; an inner protective layer positioned inward of the outer protective shell so as to substantially cover the inner surface of the outer protective shell wherein the inner protective layer includes a plurality of air channels formed in an inner surface of the inner protective layer with at least one of the channels extending from at least one intake opening to the at least one exhaust opening; a liner including a liner retention mechanism for securing the liner in the interior of the helmet, the detachable retention mechanism comprising: at least one opening extending in a direction that is generally parallel to a perimeter of the eye opening wherein the at least one opening defines a recess with at least one blocking surface that is generally normal to a plane of the at least one opening; at least one tab having a main body and an engagement surface extending therefrom, wherein the main body is sized so as to be positioned in the recess defined by the opening such that the engagement surface of the tab engages with the blocking surface of the at least one opening so as to inhibit removal of the tab from the opening to maintain the liner in an engaged position with the helmet wherein the tab is deformable such that the tab can be deformed so as to disengage the engagement surface from the blocking surface to permit the tab to be removed from the opening to facilitate removing the liner from the helmet.
 19. The helmet of claim 18 wherein the at least one tab has a generally trapezoidal cross section. 